Device for bending metal bars



Oct. 31, 1933. H. BOTTNER DEVICE FOR BENDING METAL BARS Filed May 23, 1951 IIH II II] jli'inrlul i Patented Oct. 31, 1933 UNITED STATES DEVICE FOR :BENDING METAL BARS Heinrich Biittner, Cassel, Germany Application May 23, 1931, Serial No. 539,564, and in Germany September 29, 1930 6 Claims. (01. 153-45) There exist already bending machines for metal bars in whichbending disks or bending arms are provided which bend not only the end hooks, but also the intermediate portions. 'The 5 present invention relates to an improved machine for the purpose stated, and the main characteristic features of this machine are these that the 3 bending disks used in this case are vertical and are designed as toothed segments which are driven directly by toothed gearing. There are two such spaced disks, and between them are adjustable bending rods, which may have any desired length, although there are limits fixed by practical and economical reasons. Arranging the 15, bending disks in vertical planes affords the advantage that the driving gear cannot be injured by waste pieces resulting from the working procedure, and besides it is easily possible to bend all sorts of bars in any desired manner because 20 of the adjustability of the bending rods connected with the bending disks. The vertical arrange ment of the bending disks presents, furthermore, the important advantage that a plurality of bars arranged side by side can be bent in a common working procedure; in fact, even rods canbe bent at the same time. I

The centre or fulcrum of the bending disks-does not coincide with the axis of the bending rod around which the ends of the rods are bent that are to be provided with end'hooks, but said centre or fulcrum lies above the bending rod in consequence whereof it is possible to shift the rod 18 with the bent rods in the longitudinal direction of the frame-of the machine and to adjust them accordingto the requirement, viz. to the position of the intermediate bends to be made. The bending' rod is preferably shiftable in grooves or slots provided in the side members of the frame of the machine, and it is suited to the purpose in view to provide notches in said grooves or slots,-these notches constituting then a sort of scale with the aid of which a big number of rods can be bent perfectly uniformly just as adjusted. v

If shearing bends are not required, but the rods are to be provided with hooks at both ends, it is easily possible to draw the rods stra'ightwa'y through the machine after the hooks have been formed at the one end, after which the rods'are inverted and now the other ends are introduced into the machine in which then the hooks at these ends are formed.

The invention is illustrated diagrammatically and by way of example on the accompanying drawing on which Figure 1 is a vertical longitudiml section through a bending machine designed according to this invention; Figure 2 is a plan of the machine, the uppermost members being, however, shown in horizontal section, viz. in the plane indicated by 22 in Fig. 1; 11 in Fig. 2 indi catesthe plane of section for Fig. 1; andFigure 3 is a front-view of the machine.

1 and 2 denote the lateral frame parts of the machine. From the middle portions of these frame parts extend upwardly vertical standards 10 and 11in which toothed segments 8 and 9 Constituting the bending disks are supported upon pivots 14. Each segment is in gear with a pinion (6 and 7), the two pinions being connected with one another by a common shaft, and at one end of this shaft is a cog-wheel 5 meshing with another cog-wheel 4 that can be manually turned by means of a crank 3. The toothed segments can be turned in eitherdirection according to the direction of turning of the crank 3. Instead of the manual driveamotor drive may, of course, be provided. V

The segments 8 and 9 are connected with one another by rods 12 and 13 arranged counter to one another, also relatively to thepivots 14. The

rods 12 and 13 are prevented from .turning by upon a table 24. Besides the bending rods 12 and 13 that are movable together with the disks 8 and 9, there is below these disks a stationary bending rod 23 and a horizontally movable bending rod 18 which can be drawn forward in slots 19 in the lateral members'of the machine by means ofa grip 22 so that the distance between the rods 18 and 23 can be varied according to the distance required between the end hook 21 of the .rod and the first bend 25 of the same, that change of position being effected after the hooks 21 have been bent by means of the rod 12, it being understood that the distance between the rod 18 and the pivots 14 is at that time the same as the distance between said pivots and the rod 12. When the hooks have been formed, andif the distance between them and the nearest bend to be made (25) is to be greater than the distance between the rods 23 and 18, this latter rod is pulled to the right as much as necessary, after which the next bending phase takesplace.

The grip 22 is shown in full lines, as well as (in another position) in dotted lines. When the grip is in this latter position, the rod 18 is in the position 18 in which case the distance between the hook and the first bend of the rod is, of course, considerably longer. The arrow P indicates the direction of action of the bending rod 12 and the arrow K indicates the direction of action of the bending rod 13. The rod 12 produces the hook and the rod 13 produces the two intermediate bends. ihe direction of turning of the segments 8 and 9 is in this case, of course, counter to that direction of turning by which the hooks 21 are formed. The bends and 26 are produced at the same time, as will be clear WltllOllt a more detailed explanation. Also the distance between the bends 25 and 26 can be varied by adjusting the table 24 in height, for.whichpurposestepped supports for it are provided, and accordingly the bending rod 13 is inserted into another opening, viz. 15 or 17, as required. It is, finally, possible to remove the otherwise stationary bending bolt 23, in which case only the bend 26 Will be produced besides the hook.

In order to vary the radius of the curvature of the hooks,.as wellas of the bends, pieces of tube may be shovedupontheseveral bending rods (12, 13,18, 23).

In order to exert a counter pressure uponthe rods while they are. subjected to the bending operation oblique slots 28 and in them heavy iron bars 270i; flat. section are provided, these bars pressing upon the rods 20, but giving way according to the thi'cknessofv the rods 20;

The iron barsv 20 are generally of circular crosssection. If theyare. comparatively thin; a separate. clamping devicemay be provided which consists of transverse superposed ledge s 29-and3l, of. which the upper ledge '29can be. loosely turned on thethreaded'shaftofa bolt SOlocatedinthe lower ledge 31. Theupper ledge can be'turned into the position shown in dotted lines in-Fig. 2, (position 29') mod when it is in this position, the iron bars can be. placed side by side. upon the lower ledge, whereafter the upper. is turnedback into itsforrner position,.in.which.it is-then secured'by the threaded bolt 30, the ironbars-being now properly held intheir position in .whichthey are worked.

The operation of the machine is as follows: At the beginning of theoperation the-bending rod:18 which: is at rest while'the first bending phase,- the formationof the hooks 21,.isgoing on, is located practically below themovable bending rod 12 and the radius between it and the' pivots l has the same lengthas the radius between these pivots' and'the'rod 12. Now thestraiglit bars 20are introduced'into the machineand'shovedso much thereinto that there free ends extend as must beyondthe rod l8-as'is requisite for the formation of the hooks 21. Now the segments 8 and 9 are turned in the proper direction (clockwise in Fig. 1) until the rod 12 presses upon the projecting ends of the'rods 20 and'bends them round the rod18so as to transform them into the hooks 21.

Then the. segments 8 and 9.. are turned in the reverse direction until the rod 16 presses upon the bars 20 and. bends them downwardly over the rod 23 so as to form the bends 25, and immediately thereafter also the bends 26 are formed; they are finished when the rod 16 contacts with the table 21-by which the. movement of the seg ments isterminated.

The entire device may be stationary or portable, as preferred.

I claim:

1. A device for bending metal bars at their ends and near the ends, comprising, in combination, spaced vertical bending disks and-bending rods in them, these rods being arranged counter to one another with respect to the centres of said disks; a third bending rod arranged below the disk centres in the frame of; the device, oblique slots provided in lateral, members. of the frame above the rods to be bent, and freely movable metallic members adapted to bear upon the bars, and means for turning the said disks, substantially as set forth.

2. A device for providing metal bars with bends at. their ends and near their ends, comprising, in combination with a pair of spaced vertical bending. disks and with transversely arranged bending rods-located in said disks, a frame supporting the disks and having longitudinal guide slots below them, a third bending rod supported in said slotsand being shiftable therein; inithe direction of the bars to be bent, and; a table-so arranged as to carry thesaid bars, substantially as set forth 3. A machine for bending metalbarsincluding two oppositely located turnable members, amovable bending rod extending fromone of. said members to the other. thereofand being'moved by them in a. circular path, and av stationary bending rod around which the bartobebentis shaped, said machine comprising, in combination with the'parts stated, another movable bending rod also extending from one; of; said turnable members to; the other thereof and. being; located diametrically opposite with respect tO theEfiI'St? mentioned stationary bending rod, and another stationary bending; rod located laterally from said'nrst-mentioned stationary bending rodon the side of said; second: movable bending: rod; and a table located, on a lower level than: all said rods on that vside of the machine: where thereare' the second stationarybending rodand the second movable bendingrodand serving: as

abutment for this latter rodnandrthebars-'ithas bent over the saidsecond stationary bending rod whereby said bars are PI'OVidGdLWillh-WVQODDO sitely located bends.

4. A- machine for bending metal barsincluding two oppositely located turnable: members; 3/.II10V-'- able bending rod extending from one: of: said members to-theother thereof and being moved by them in a circularpath, and. a stationary bending-rod around which thebarato'be bent is shaped; said machine comprising; in. combination with the parts stated, another." movable bending rod also extending. from one of?v said turnable members to the other thereof and being located diametrically opposite with respect? to the first-mentioned stationary bending rod and adapted to be adjusted to several different dis tances'from the fulcra of the turnable' menu-.- bers; and another stationary bending" rod located laterally from said first-mentioned stationary' bendingrod. on the sideofsaid; second movablebending rod, and a table-locatedionia lower level than all said rods on that. side of. the machine where there are the second stationary bending rod and;- the second movable bending rod and serving as abutment for this latter rodand the bars it has bent over the said second stationary bendingrodwhereby; said bars are provided with two oppositely located bends.

5; A machine for bending metal bars-including two oppositely located: turnablemembersiamovable bending rodextending from one of said members to the other thereof and being moved by them in a circular path, and a stationary bending rod around which the bar to be bent is shaped, said machine comprising, in combination with the parts stated, a frame supporting said turnable members and having in its upper rims downwardly extending oblique slots;

a heavy transverse bar'loosely movable in said slots and bearing upon the bars to be bent; another movable bending rod also'extending from one of said turnable members to the other thereof and being located diametrically opposite with respect to the first-mentioned stationary bending rod, and another stationary bending rod located laterally from said first-mentioned stationary bending rod on the side of said second movable bending rod, and a table located on a lower level than all said rods on that side of the machine where there are the second stationary bending rod and the second-movable bending rod and serving as abutment for this latter rod and the bars-it has bent over the said second stationary bending rod whereby said bars are provided with two oppositely located bends. V

6. A machine for bending metal bars including bending rod around which the bar to be bent is shaped, said machine comprising, in combination with the parts stated, another movable two oppositely located turnable members, a movbending rod also extending from'one of said turnable members to the other thereof 'and'be:

ing located diametrically opposite with respect there are the second stationary bending rod and the second movable bending rod and serving as abutment "for this latter rod and the bars it,

has bent over the saidfsecond'stationary bending rod whereby said bars are provided with two oppositely located bends, and stepped sup-V ports for said table permitting to adjust it in several heights in order to vary thedistance between said two bends,

. HEINRICH BO'ITNER. 

